Piotte M, Beaudet A, Brawer J R
Department of Anatomy, McGill University, Montreal, Que., Canada.
Brain Res. 1988 Jan 26;439(1-2):127-37. doi: 10.1016/0006-8993(88)91469-2.
The topography, fine structure, and patterns of connections of tyrosine hydroxylase (TH)-immunoreactive tubero-infundibular dopaminergic (TIDA) neurons were examined by light and electron microscopic immunocytochemistry in the arcuate nucleus of 2-, 15- and 30-day-old female Wistar rats. In 2-day-old animals, TH-immunoreactive perikarya were mainly located in the ventrolateral portion of the arcuate nucleus. In 15-day-old rats numerous TH-positive cell bodies were still present ventrolaterally, but a cluster of labeled cells was also apparent in the mediodorsal segment of the nucleus. In the 30-day-old rats, most TH-immunoreactive neurons were concentrated mediodorsally, as seen in the adult. At the ultrastructural level, TH-immunoreactive somata exhibited, in all age groups, a large nucleus surrounded by a thin rim of cytoplasm containing mitochondria, Golgi apparatus, endoplasmic reticulum, multivesicular bodies and lysosomes. These labeled somata were synaptically contacted by unlabeled axon terminals and often laid adjacent to either labeled or unlabeled dendrites. Similarly, in all age groups, labeled dendrites were synaptically contacted by unlabeled axon terminals and were often directly apposed to either labeled or unlabeled perikarya and dendrites, or to tanycytic processes. These results indicate that TIDA neurons establish extensive connections early in development, and that their pattern of intercellular relationships remains qualitatively unchanged from 2 days to adulthood. It is suggested that TIDA neurons may be already functional at birth, and could therefore, influence the maturation of other arcuate neuronal populations.
通过光镜和电镜免疫细胞化学技术，对2日龄、15日龄和30日龄雌性Wistar大鼠弓状核中酪氨酸羟化酶（TH）免疫反应性结节漏斗多巴胺能（TIDA）神经元的形态、精细结构及连接模式进行了研究。在2日龄动物中，TH免疫反应性核周体主要位于弓状核的腹外侧部分。在15日龄大鼠中，大量TH阳性细胞体仍位于腹外侧，但在核的中背段也可见一群标记细胞。在30日龄大鼠中，如在成年大鼠中所见，大多数TH免疫反应性神经元集中在中背侧。在超微结构水平上，所有年龄组的TH免疫反应性胞体均表现为一个大核，周围有一层薄的细胞质边缘，其中含有线粒体、高尔基体、内质网、多囊泡体和溶酶体。这些标记的胞体与未标记的轴突终末形成突触联系，并且常常与标记或未标记的树突相邻。同样，在所有年龄组中，标记的树突与未标记的轴突终末形成突触联系，并且常常直接与标记或未标记的核周体、树突或室管膜细胞突起相邻。这些结果表明，TIDA神经元在发育早期就建立了广泛的连接，并且它们的细胞间关系模式从2日龄到成年期在质上保持不变。提示TIDA神经元在出生时可能已经具有功能，因此可能影响其他弓状神经元群体的成熟。
